The present invention relates to a brake disc rotor of a disc brake device for a vehicle. More particularly, the invention relates to a ventilated type brake disc rotor in which fins are radially provided between opposed disc plates and ventilation holes are opened between the fins.
Society of Mechanical Engineers paper (Vol. 55, 122nd issue, No. 88-0622A) and Japanese Patent Application Laid-Open No. 9-280278 disclose conventional ventilated type brake disc rotors.